Windows 7 Having a lot of issues with Explorer.exe

[RhinoBlindado]

Hello, so I came back from studying 5 months in another state, and since I came to turn my PC on for the first time since October I found out that the Windows explorer was brainfarting a lot, affecting other functions like the Windows Update, Desintallation/Installation, and other Windows functions, it didn't affect any 3rd party program though.

Some of the things that have been happening:

• Windows Updates freezes at a certain percentage and never finish to install when turning off, thus having to manually shut down the PC. This stopped happening when I got to install the remaining updates
• The installation process of programs takes too long to start
• Desintallation from the Control Panel may freeze the window, don't work at all or take too long and when logging of or shutting down it displays quickly "Too many 16-bit programs are running"
  
• Trying to modifcy certain things (like deleting an empty folder inside "All Programs" in the Start Menu, or trying to change something in the Networking options) crashes the Explorer and afterwards it stops working properly, displaying "The remote procedure call failed and did not execute"

And I didn't experience any of this before, this PC is almost 4 years old, and it has been running smoothly all the way without any significant problem and I've never resintalled Windows.

I suppose the easiest way is to just reinstall Windows, but I'd like to leave that as a Plan C, I got a lot of important files that take a lot of space and I don't know if my other PCs could handle that.

Any Ideas of what to do?